Mr. Forster, whom I have known since 2003 or so, spawned Calibre Mining (TSX: V.CXB, Stock Forum), a Nicaragua gold and copper explorer. The shares are on fire. (And yes, I own ‘em and have for more than two years.)

“When Dr. Copper is in the house, it’s a very, very, very good house,” says Don Mosher. Don represents Riverstone Resources (TSX: V.RVS, Stock Forum), a Burkina Faso prospector whose shares look ready to bust out after a largely ignored resource report. A geologist I rely on for analysis, Dr.Peter Megaw of Minaurum Gold (TSX: V.MGG, Stock Forum),Candente Gold and others, told me, “Copper is a big-company business. A billion tonnes of half-percent copper with the gold credit blended in, that takes care of a lot of the risk of taking on a development.”

Mr. Forster is executive chairman of Calibre, whose exploration chief, Greg Smith, has his team smack in Nicaragua’s mining triangle. That’s in the northeast part of the nation. (Photo: Greg Smith with sample – Thom Calandra photo) The Primavera “discovery hole” printed 262 meters of 0.78 gram-tonne gold and 0.3 percent copper. The drill assays followed revealing channel samples released to the public in November.

“Because you are dealing with bulk mineable deposits, the copper-golds can contain world-class resources such as at Donlin Creek, Cerro Casale, El Morro, Agua Rica,” says Mr. Forster, whose financings have assisted other companies, including Edgewater Exploration (TSX: V.EDW, Stock Forum) in Spain. “With pure gold vein deposits you have to drill close spaced holes and it takes a lot longer to be able to tell investors what the potential is, and the potential is generally less than with a porphyry opportunity.”

Copper’s price is on a run this month, near a four-month high and within reach of record highs. Gold miners can credit copper production revenue against gold production costs and report only gold production with low cash costs per ounce. Copper miners can credit the gold production and produce copper at low cost.

At Calibre’s project in Nicaragua, vein gold deposits crop out on surface “because they are quartz veins,” says Mr. Forster, a Vancouverite. “Primavera did not crop out because it weathers recessively. We didn’t know what we had until we trenched the soil geochem anomaly.”

Trenches sometimes can help discerning investors read the tea leaves at a fledgling project. In the case of Primavera, six trenches returned fairly lengthy stretches of mineral: one was 179 meters of 0.6 gram-gold and almost 1,000 parts per million of copper.

Regulus Resources (TSX: V.REG, Stock Forum) in northern Argentina, a recent spinoff in the sale of mother ship Antares Minerals of Peru, saw its stock go ballistic in December after a 50-50 project with Pachamama showed the right stuff in a drill hole. It released a deep intercept just before the Christmas holiday. The potential copper-gold deposit showed the potential for bulk underground mining and open pit development.

“We like the fact this gives us the protection of both metals,” Kevin Heather, a director of Regulus, told me at the Cambridge Show.

“Poly-metallic mines and properties are always in demand,” Tom Macneill says. I came across Mr. Macneill, a lifelong Saskatchewan resident and longtime chief of 49 North Resources (TSX: V.FNR, Stock Forum), across the street from Vancouver’s Waterfront at lunchtime. Tom is sitting on his merchant bank’s 10-percent-plus ownership of surging DNI Metals (TSX: V.DNI, Stock Forum). DNI is a northern Canada smorgasbord of elements in an expansive property portfolio. I am fortunate to own FNR and DNI after Joe Martin, organizer of the Cambridge shows across Canada, California and Arizona, introduced me to Tom M. two years ago. (Photo: Joe Martin, at right, in Vancouver show broadcast – Thom Calandra photo)

Greg Smith, exploration chief at Calibre Mining, tells me if drill results like the ones from a week ago continue to show mid-grade copper across vast swaths of land at Primavera, Calibre’s partners will start calculating projected mine life by the decades instead of the years. We’ll see. I pledge here to hold my almost 200,000 shares of Calibre for at least another three months.

In the world of tiny: Dr. John Clarke, a geologist I know from years ago during his days with Nevsun Resources in Eritrea, is now a director of PMI Gold (TSX: V.PMV, Stock Forum). Last summer, I fell in love with PMI’s Ghana property, Obotan, which could start producing gold from a vast waste pit and surrounding properties within 15 months. Dr. Clarke says he has an interest in a tiny Turkey copper & gold prospector, Mediterranean Resources (TSX: T.MNR, Stock Forum). Turkey has only a handful of metals prospectors that trade publicly. I own PMI (TSX: V.PMV, Stock Forum) shares but not Mediterranean.

I think we’ll see a few more copper-goldies pop off the shelf in coming weeks. One of them is in our Torrey Hills Capital portfolio of clients, EurOmax Resources (TSX: V.EOX, Stock Forum). Its Ilovitza copper-gold property is in Macedonia. On the poly-metallics, another Torrey Hills client, Revett Minerals (TSX: T.RVM, Stock Forum), has several metals in production at its Troy Mine. I’ve owned Revett shares mostly as a silver-zinc-copper stock since visiting Troy a couple of years ago.

Not long ago, I saw Boxxer Gold’s (TSX: V.BXX, Stock Forum) Boss copper property near Las Vegas in Nevada. Elmer Stewart showed me around the skarn-hosted plains. I saw plenty of visible and oxidized copper, which is no “sure” indicator of economic value when drills start piercing the limestone and marble beneath the desert floor. I mention Boxxer here because it is probably the cheapest thing out there in my world of possible copper-gold porphyries. If coming assays prove to host mediocre copper grades across lengthy meters, the 13-cent stock easily would quintuple in a short stretch of days. I don’t own it, but I might buy in.

My biggest personal bet on copper-gold is Bellhaven Copper & Gold (TSX: V.BHV, Stock Forum). I own almost two million shares now, and the Colombia and Panama prospector is not a client of Torrey Hills. La Mina in Colombia has enormous copper-gold potential; the compliant resource is something like 1.6 million ounces gold equivalent.

That part of Colombia is called the Middle Cauca Belt; in and around La Mina I have great respect for David Forest & Colin Andrews’ Sunward Resources (TSX: V.SWD, Stock Forum), whose gold-copper project at Titiribi I have seen thrice now but do not own.

I don’t know if you have seen the latest assays on Sunward’s Cerro Vetas. They appear to dispute the notion that Titiribi grades are just mediocre. Dave Forest, the chief operating officer, calls the three-plus grams-tonne gold across 38 meters “the most significant development with the project since we first started drilling.” Lots of copper, too, as I recall from my visits. I think closely held SWD shares will boom well above the $2 level in very short order here. I don’t own ‘em.

Notes: Both the Cambridge Bash and B.C. Round-Up were outstanding. The two shows brought at least 700 companies to town and almost 10,000 people. A new pavilion at Round-Up took me through 100 years of British Columbia metals exploration. … See you at Indian Wells, California, in two weeks (Feb. 11-12): Cambridge House Investment Show.Read my feed. … Here is an interview I did in Vancouver.In the video, I talk about my views on geopolitical risk … and the mistakes I have made in the past, including my failing to disclose trades when I was writing a subscription newsletter eight years ago.

– Thom Calandra is an author whose work has appeared in newspapers, newsletters, magazines and across the Web. He is a founder of CBS MarketWatch, now Dow Jones MarketWatch. He is a member of Torrey Hills Capital in Del Mar, California. Clients provide stock options to Torrey Hills in return for investor outreach services. See: babybulls.com, which is a Torrey Hills Capital property.